I had my HPI RS4 3SS for the past 4 years and it was a bit of a pain after buring almost less than 1 gallon of fuel as all of its outdrives (diff, axle, & transmission) front and rear wore out quickly, thus, I have to upgrade it to hardened one. The picture posted by Harald1966 depics the same situation that I had before, therefore, I would conclude that this is a recurring issue for most HPI kits, especially if you are a frequent user of stronger and faster motors. To address this concern, I would suggest that you upgrade your outdrives to hardened ones. I am not soo sure if there is already a hardened version of this.

Once I've sold my Yokomo MR4TC, I will consider getting one of these HPI Sprint 2. I'll use my existing electronics and motors though.

BTW, since this car have gear diffs, can this be finetuned using silicone diff oil ? I can't find an exploded view of this cars differential. []